Field help:
... including foreign investment income
... including capital gains that are subject to withholding tax
Specify the foreign capital gains which are subject to withholding tax or which would be subject to withholding tax in Germany.
If applying for unlimited tax liability or applying for the personal and family-related tax benefits, the amount of foreign income earned during the time abroad which was not subject to German income tax must be checked.
Income in foreign currency must be converted on a monthly basis using the euro reference rate of the European Central Bank. If wages are paid in the currency of the country of employment, they must be converted at the monthly average euro reference rate published by the European Central Bank (Ministry of Finance (BMF) letter dated 3.5.2018 ( IV B 2 - S 1300/08/10027, BStBl 2018 I p. 643).
Here is an overview of the annual conversion rates for the key foreign currencies.